Wheel dressing device



Dec. 14, 1943. o. sTQRz` V 2,336,650

WHEEL DRESSING- DEVICE .F'iled Jan. 16, 1941 3 Sheets-Shee?l l s sheets-sheet 2` ll V |51 O. SLI-GRZ WHEEL DRESSING DEVICE Filed Jan. 16, 1941 Dec. 14, 1943.

Dec. 14, 1943. o'. sToRz v 2,336,650

WHEEL DRESSING DEVICE Filed Jan. 1s, 1941 :5 sheets-sheet s |l dlflnufe 119 01% y0/j l. 9%M049 Patented Dec. 14, 1943 UNETED STATE gaat Manufacturing Com corporation of Indiana Application January 16, 1941, Serial No. 374,719

12 Claims.

This invention relates generally to a method and devices for dressing grinding wheels and in particular an improved method and device for putting a radius on grinding wheels having concavely curved peripheral surfaces.

Wheel dressers in the prior art of the type adapted to put the same radius on a pair of cooperating grinding wheels are generally complicated in structure, bulky and inconvenient to handle, and expensive in cost. Further, the adjusting of this type of wheel dresser to properly set the cutting position of the dressing tool is rather diicult and usually requires a plurality of adjustments on each of two or more parts ci the device. The complexity and number of all of the various adjustments not only makes the setting up of the dressing tool a diiiicult operation but also tends to impair the accuracy of the setting. Since it is not unusual in the use of many grinding machines to have to dress the wheels as often as twice an hour, much time is thus lost in the dressing operation so as to unnecessarily increase the overall cost of the grinding operation.

Another diiculty in these prior art devices, and particularly in those which utilize a diamond cutting tool is found in the 'fact that the adjustments for setting the tool assume the high point of the diamond to be exactly at the longitudinal axis of the diamond. Where the high point is off-set from such axis, the accuracy of the setting is in error by an amount corresponding approximately to the magnitude of the ofi-set. Diamond cutters in which the high point of the diamond is centered exactly at the longitudinal axis of the diamond are extremely expensive in cost and appreciable savings can be made, therefore, if a diamond having an ofi-set high point can be eiciently used.

It is an object of this invention, therefore, to provide an improved dressing device for a grinding Wheel.

Another object of this invention is to provide an improved method for dressing grinding wheels.

Yet another object of this invention is to provide van improved device for dressing grinding wheels, which is simple, compact, and rugged in construction, eiiicient in operation and cheap in cost.

A further object of this invention is to provide an improved dressing device which is capable of putting the same radius on two cooperating grinding wheels with a minimum of adjustments and with but one setting of the dressing tool.

A still further object of this invention is to pany, Valparaiso, Ind., a

provide an improved dressing device for putting a radius on a grinding wheel, which is equally accurate when operating with a diamond cutter having an o-set high point or a high point at its axial center.

A still further object of this invention is to provide an improved dressing device which is easy to handle, simply and quickly adjustable, and readily assembled in an operating position on the grinding machine to in al1 appreciably reduce the time required for the dressing operation.

A feature of this invention is found in the provision of an improved dressing device for putting the same radius on a pair of cooperating grinding wheels which is comprised of two main parts to facilitate its handling for assembly on and removal from the grinding machine. The device is adapted to position the cutting tool rbetween the two wheels and to provide for a linear adjustment of the tool in three planes to a proper cutting position relative to the two grinding wheels. The device further includes means for rotating the cutter tool when in its set position so as to dress the wheels successively with but a single tool setting.

Further objects, features and advantages of this invention will become apparent from the following description when taken in connection with the accompanying drawings in which:

Fig. 1 illustrates the invention in operating position on a grinding machine, the tool carrier being shown in section;

Fig. 2 is a sectional view as seen along the line 2 2 in Fig. 1;

Fig. 3 is a sectional view as seen along the line 3 3 in Fig. 1;

Fig. 4 is a fragmentary detail View partly in section showing the cutting end of the improved device and the assembly thereon of a gauge for initially setting the cutting tool;

Fig. 5 is a sectional view taken along the line 5 5 in Fig. 4

Fig. 6 is a plan View of the invention;

Fig. 7 is a side elevational view as seen along the line 'I 'l in Fig. 6; and

Fig. 8 is a fragmentary sectional view as seen along the line 8 8 in Fig. 7.

In the illustrations the improved dressing device is shown with a grinding machine having a pair of cooperating grinding wheels formed with peripheral surfaces of concave form. The device includes a base member which is slidably supported for horizontal movement on the working carriage of the grinding machine, and has mounted at one end thereof a carrier unit for the diamond or cutting tool. The supporting base and carrier unit are of a construction to position the cutting tool between the grinding Wheels and approximately in a, plane common to their axes. The cutting tool is carried at the lower end of an arm which is pivotally supported in a rotary hollow shaft which in turn is journaled in a stationary guiding sleeve, the arm, shaft and sleeve being formed as part of the tool carrier unit. Adjusting means at the upper end of the hollow shaft pivotally move the pivoted arm to move the high cutting po-int of the diamond in, or substantially in the plane common to the axes of both grinding wheels. Linear adjustment of the diamond to a center position radially of the wheels is accomplished by movement of the base portion relative to the carriage of the grinding machine, while a transverse centering of the diamond relative to the wheels is accomplished by moving the carriage with the base portion in a fixed position thereon. With the diamond properly adjusted, the hollow shaft is rotated concurrently with a rotation of the grinding wheels, the wheels being successively dressed during one complete revolution of the diamond.

With reference to the drawings the invention is shown in Fig. 1 operatively assembled on a grinding machine, and mounted on a portion Ill of the frame structure thereof. The grinding machine is illustrated as including a pair of cooperating grinding wheels II and I2 radially spaced apart and having their axes lying in a common horizontal plane. The peripheral grinding surfaces I3 and I4 of the wheels II and I2, respectively, are of concave form with curvatures of like radius, or may at least be dressed by the present improved tool to the same curvatures, and are adapted for the grinding of bearing race rings or the like. The frame I is provided with a track or way I6 for guidably supporting a carriage I1, the carriage I1 being movable transversely of the wheels I I and I2 by suitable means (not shown). The carriage in turn is formed with a track I8 for slidably supporting the horizontal portion I9 of a base or mounting member 2| for the wheel dresssing device. Movement of the base member 2l radially of the wheels I I and I2 and relative to the carriage I1 is accomplished through an abutment 22 integrally formed on the carriage I1 and having a threaded aperture formed therein for engaging a drive screw 23. The drive screw 23 is rotated by a hand lever 24 mounted at one end thereof, the movement of the portion I9 being measured by the micrometer indicia shown at 25.

Integrally formed with the horizontal portion I9 of the member 2| is a vertical or end portion 26 which projects over the wheels II and I2 and has a bore 21 extending vertically therethrough. The bore 21 is countersunk at the top thereof to form an annular shoulder 3B and is of a size to slidably receive in guiding engagement a guiding or outer sleeve 28. The sleeve 28 is provided with an axially extending key way 29 (Fig. 8) which cooperates with a key 3| secured in the supporting member 2I to prevent rotation of the sleeve in such member. To facilitate the insertion of the guiding sleeve 2S within the bore 21, the portion 26 is split as at 32 (Fig. 6) to permit a spreading of the bore. The sleeve slides through the bore 21 until the annular shoulder 33 at the top thereof engages the shoulder 39, this engagement defining the assembly position of the sleeve in the base 2I. The sleeve 28 is frictionally locked in this position by the tightening of the screws 34 in an obvious manner. By virtue of the vertical arrangement of the bore 21 in the portion 26, the guiding sleeve 28 is, therefore, firmly locked in a position at right angles to the common axial plane of the wheels II and I2.

Arranged within the sleeve 29 is a hollow shaft or spindle 36 which extends outwardly from each end o-f the sleeve and is rotatably supported therein by bronze bearings 31 and 31A or the like, the bearings being seated within annular recesses formed in the inner peripheral surface of the sleeve 28 near each end thereof. The shaft 36 is retained in its assembled position within the guiding sleeve 28 and adjusted axially relative thereto by means of an adjusting collar 39 which is threadably engaged with the shaft at its threaded upper end 4I, and is positioned between the sleeve 28 and the shaft 36 in an annular recess 42 formed in the annular flange or shoulder 33. The collar 39 is provided further with an overhanging lip portion 43 which is in retaining engagement with an annular rim 44 formed on the flange 33. Adjustment of the collar 39 also serves to adjust the axial play of the bearings 31 and 31A. A fibre washer 40 and a metal washer 40A are located between the collar 39 and upper bearing 31A, the washer 40 protecting the bearing from dirt and grit and the washer 40A rotatably supporting the colllar 39 and hence the shaft 3G. A fibre washer 45 and a steel washer 45A are similarly provided between the lower end of the bearing 31 and the shaft 36. The adjusted position of the colllar 39 is retained by a locking nut 48, which is tightened about the threaded end 4I of the shaft 36 into frictional engagement with the collar.

Axially arranged within the hollow shaft 36 and extending outwardly from the lower end 49 thereof is a holding or pivoted arm 5I, the dressing tool or diamond 52 being mounted at its lower end V53 and frictionally locked therein by screws 55. (Figs. 1 and 2.) Arm 5I, substantially near the center thereof, is pivotally supported on axis means 54 in the shaft 35, and is tapered down- Wardly from such center toward each of its ends, the lower end 53 and the upper end being formed with similarly shaped rectangular portions 56 and 69, respectively. (Figs. 1, 3, 5, and 7.) By virtue of this tapered construction and pivotal support of the arm, the arm is pivotally movable within the shaft 36 in a plane normal to the pin or axis 54. The taper also serves to lighten the shaft, without impairing its strength. Since the dressiing device is usually manually assembled on the grinding machine this reduction in weight provides for an easier handling thereof.

Positioned about the end portion 59 and within the shaft 36 is a bushing or collar 51 having a rectangularly shaped aperture 58 therein of a size to slidably engage the opposite side walls 59 of the portion B0, while permitting relative movement between the end walls 6I and 62 of the portion 60 and aperture 58, respectively (Figs. l and 3). The lower end 53 of the arm 5I is similarly guided at the portion 56 in a rectangular aperture 63 (Fig. 5) formed at the lower end 49 of the shaft 36. The arm 5| is thus guidably supported for a pivotal or swinging motion between the grinding wheels II and I2, this motion moving the diamond 52 in an arcuate path with the pivot point 54 as a center for a purpose to be later explained.

Rotation of the sleeve 36 and hence of the holding arm 5l which is .pivotally supported therein, is accomplished by .a gear mounting member Eli which is threadably secu-red .to the shaft 36 at its .threaded end 4l.. The mount .64 is provided with a worm gear 55 which fis Africtionally locked thereon by a. friction collar 61 and locking nut 68. Gear 6.6 is .in driven engagement with a worm gear e9 (Figs. 1 .and 6) mounted on a shaft 'l'.l, which is rotatably supported in a bracket memebr .l2 secured to .the guiding sleeve 28. The shaft .'ll is rotated by a handle i3 provided at one rend thereof to .in tu-r-n rotate the shaft 36 Vthrough the gears :56 and V69.

ln order to Afacilitate the handling .of the `truing mechanism it is .contemplated that .the supporting means or carrier M for the diamond V52, which includes `the sleeve E8, and the assembly of the rotary means, namely, the arm 5l, shalt 3S `and gear assembly '56*89, be removable from and inserted within the mounting `portion `2l as Ia unit. The necessity of handling the complete device as a unit is, therefore, unnecessary, and the device is simply positioned in place on the grinding machine by the separate handling oi 'i 4the sliding or base ing means 14.

In the operation of the truing device, let it be assumed that a radius of l inch is to be put on the peripheral surfaces i3 and i4 of the grinding wheels H and l2, respectively. The base portion 2l is slidably engaged with the track I8 on the carriage Il, the bore 21 in the end portion 5 of the base member being vertically arranged or at right angles to the horizontal plane which is common to both of the axes of the wheels il a-nd I2, the plane being indicated at lr6. By lvirtue of the open position of the split 32, and hence of the bore 2l, the carrier 'F4 is readily `inserted within the bore 2l, with the key way 29 and key 3! in cooperating engagement, and dropped therein to a position determined by engagement of a spring-pressed latch 'il (Fig. 8) in an aperture 78. Aperture 18 is formed at the bottom of the key way 29, the latch 'il being guided thereto by its position within the key way. This position of the carrier member 'l is such that its lower end extends below the end portion 2li a distance suilcient to provide for the attaching of a gauge member 7S thereon (Fig. 4). The gauge 79 is of ring shape and adapted to iit about the lower end in of the hollow shaft S5. A split portion 8l is formed at one side of the gauge, engaging screws S2 therein serving to frictionally lock the gauge about the shaft end 9 in an obvious manner. Integra-ily formed with the gauge is an extension or arm 83 having an outer surface Sil spaced a predetermined distance away from the rotating axis or axial center of the spindle 36. By way of example, let it be supposed that this distance is 2 inches, as indicated by the lines A-A in Fig. 4. This gauge measure ment is predicated on the arm 5l beinCr vertically positioned or centered within the shaft 36 which position is shown in Fig. l. Adjustment of the' arm 5! within the shaft to a center position. or in fact to any desired position within the limits of movement thereof, is accomplished by micrometrically adjustable screws 83 (Figs. 1 and 3) which are engageable with the opposite sides 6l of the arm portion 58 and threadably secured in the gear mount 64 and collar or bushing 5T. By a reversed manipulation of the .adjusting screws S5 the arm 5l is pivotally moved in a desired diportion 2l and the support- -rection within the shaft, to swing the arm .end

y53 in a ,pivotal arc, to in turn move the 111001.52 relative to the plane '16, the center position of the arm being determined when the arm end 53 is at the lowest point of its .pivotal swing. The adjusted position of the arm 5I is retained .by a locking screw :81, which is also threadably secured in the gear mount 64 and collar 5l, but is arranged at right angles to the screws 86 and is engageable with one side wall 59 of the end portion E@ to frictionally lock the opposite side 59 with its corresponding adjacent side of the .aperture v58.

With the arm '5l in its center position and with the gauge 79 in its operating position at the shaft end 49, the end or high point E of the diamond 52 is set so as to be 3 inches away from the gauge surface 84. rlhat is, since the rotational axis of the diamond 52 is coincidental with the axis of rotation of the shaft 36, a one inch radius of rotation of the diamond and hence a rone inch radius on the peripheral surfaces I3 and I4, is obtained when the point E is positioned one inch away from such axis of rotation. With the surface S4 diametrically opposite the high point E and with such surface at a predetermined distance of two inches away from the axis of rotation, it is clearly apparent that the one inch radius is simply obtained .by setting the point E three inches away from the surface 84. Holding screws 55 at the arm end 53 are adjustable to lock the diamond 52 in the position as set by the gauge 19, after which the gauge TS is removed from the shaft 36 by loosening the screws 82.

On removal of the gauge 73, the spring pressed latch '11 is retracted from the aperture 'I8 and the diamond carrier 'lll permitted to drop until the annular ring 33 on the guiding sleeve 28 engages the shoulder Si) near the top of the opening 2.?. Since it is contemplated that the truing device be particularly adapted for operation with a certain grinding machine, the length of the carrier 'it in its supported position is such that the longitudinal axis of the diamond 52 lies substantially in the horizontal plane l5 (Fig. 1). The sleeve 28 is then locked within the portion 25 by tightening the screws 34 to close the split 32.

In vthe purchasing of diamond cutters it is very diiiicult to obtain a diamond in which the high point E is located exactlyat the longitudinal axis. Any misalignment of the high point E from the horizontal plane 'i6 renders inaccurate to some degree the accuracy of the radius to be cut. In other words, the radius is generally determined with reference to the horizontal plane 'I6 land such radius is varied by any positioning of the point E above or below such plane. This difficulty is overcome in the present invention by the pivoted arm or diamond holder 5l. With the arm 5l in its centered position, as shown in Fig. l, the arm end 53 is at the low spot or point of the pivotal arc for the arm. As shown in Fig. l, therefore, when the end 53 is moved toward the left, the high point E is lifted upwardly relative to the plane l, while a reverse movement of the arm end 53 lowers the point E relative to the plane iii. Any deviations of' the point E away from the longitudinal axis of the diamond point 52 are thus readily compensated for by merely swinging the arm end 53 in a direction depending upon the location of the point E relative to the .plane i6. In accomplishing this adjustment the locking ,screw .8l is retracted and the adjusting screws B manipulated to move the arm end 53 in a desired direction. When the point E is in the plane 16 the screw 81 is tightened to rmly lock the arm portion 6I! with the top of the shaft 36 while tightening of the locking screws 88' at the portion 56 of the arm 5I frictionally locks such portion with the lower end of the spindle 36 (Fig. 5). The arm 5I, therefore, is securely locked in a fixed position relative to the shaft 36 so as to be rotatable therewith.

In the cutting of a radius it is important, of course, that the curved peripheral surface of the grinding wheel be symmetrical about a center plane extending transversely or radially through the grinding wheel. In grinding machines of the type having a pair of cooperating grinding Wheels, the wheels are generally arranged in radial alignment, that is, the wheels have a common transverse plane about which they are symmetrical. One of the wheels is generally rotatably mounted on a fixed axis while the other Wheel is radially movable relative to the fixed wheel and rotatably mounted on a portion of the machine frame so as to be movable with such frame portion. As illustrated in Fig. 1, the grinding wheel I is rotatably mounted on a fixed axis while the wheel I2 is radially movable relative to the wheel II, and movable with the frame portion I0. By virtue of the carriage I1 being slidably supported on the frame portion I6 and the base portion 2| in turn supported on the carriage I1, it is readily apparent that the carrier 14 is also movable with the wheel I2 on movement of the frame portion I6. Thus in the transverse setting of the diamond 52 the carriage z" I1 is moved by suitable means (not shown) to center the point E transversely of either one of the grinding wheels or I2. Since the grinding wheels are in radial alignment the point E is thus centered transversely relative to both of such wheels. This centered position is retained by tightening the locking unit 89.

In determining the cut to be taken by the diamond 52 the point E is adjusted relative to the peripheral surface I4 of the Wheel I2 until engaging contact is made between the point and the wheel I2 at its transverse center. This relative adjustment between the diamond and the wheel I2 is accomplished by manipulation of the lever 24, which operates to move only the base bortion 2| and the carrier 14. The point E is then turned about, either by turning the knurled nut 68 or by operating the handle 13, and moved by movement of the frame portion I until the point E is in contact engagement with the peripheral surface I3 at the transverse center of the wheel II as shown in Fig. 2. By virtue of the micrometer readings for the base 2|, the contact reading of the point E and surface I4 may be noted so that the diamond 52 can be moved clear of the wheel I2, if necessary, while the diamond is being set relative to the wheel I I. A test rotation of the diamond setting is then made to determine the cut actually made in the peripheral surfaces I3 and I4. In the event one of the surfaces is too heavily cut, retraction of the point from such surface is made by a suitable manipulation of the lever 24, until substantially equal cuts are taken from each wheel, If the trial cut is satisfactory, successive dressing cuts are quickly and simply made to any desired depth. For example, suppose a .001 cut is wanted. By manipulating the lever 24 in a direction to move the diamond 52 .001" toward the grinding wheel I2, and moving the frame portion l0 .002" toward the wheel II, the diamond 52 is set to take a .001 of the wheels II and I2. Cuts of Varying depths are determined in a similar manner.

Once the truing device is set for two particular wheels, adjustment of the diamond 52 relative to the plane 16 and transversely relative to the wheels II and I2 does not have to be repeated and a dressing cut can be taken immediately on a dropping of the carrier 14 in the bore 21 and on proper adjustment of the frame portion I0 relative to the adjustment of the base member 2| of the truing device. The worm drive 66-69 rotates the spindle 36 and hence the diamond 52 at a slow and relatively steady speed. This cutting movement of the diamond cooperates with its rigid support in the base portion 2| to provide for the cutting of a smooth surface on the wheels II and I2. The flat sides on the portions 56 and 60 engaging the spindle 36 and collar 51, respectively, provide large bearing surfaces so that any chattering of the arm in the shaft is entirely eliminated. Likewise, the large bearing surface between the shaft 36 and elongated sleeve 28 eliminates any chatter between such two parts. The diamond 52 is thus positively and rmly retained in its adjusted position throughout the cutting operation.

During the dressing or cutting operation considerable grit and water is thrown from the grinding wheels onto the cutting device. It is readily apparent that the passage of any grit or abrasions into the shaft 36 and about the arm 5 I and between the shaft 36 and elongated sleeve 28 would seriously interfere with the eicient operation of the device and would appreciably shorten its service life. This dirt and grit is kept out from the hollow spindle 36 by a seal which is comprised of a pair of overlapping flat but flexible springs 9| and 52, (Fig. 4) of very small thickness. Spring 9| is of annular form, and mounted at the spindle end 49, spring 92 being of rectangular form and mounted about the arm portion 56. On pivotal movement of the arm 5|, therefore, the springs 9| and 92 are always in frictional but sliding engagement to form a water-tight seal between the arm 5| and the shaft 36. A seal 93 between the portion 26 and the sleeve 28 is comprised of a at flexible spring of annular shape which is mounted about the bore 21 at the bottom thereof and pressed into engagement against the sleeve 28. The bore 21 is thus retained free from grit so that the carrier 14 is always easily slidable therein. The fiber washers 40 and 45 at the bearings 31A and 31, respectively, which were previously explained, serve to seal and keep clean the bearing sur- .faces between the sleeve 28 and the spindle 36.

The invention thus provides a truing and dressing mechanism which is of compact and rugged construction and readily handled so as to be operatively positioned for use with a minimum of inconvenience. The cutting tool is adjustable by simple means for movement in three planes, with all such adjustments being micrometric so as to assure a maximum accuracy in the setting of the cutting point. Because of the relative m-ovements provided between the grinding wheels and the cutting point, only one setting of the cutting point is necessary to successively dress the grinding wheels. Since in many grinding machines the wheels must be dressed several times an hour, the quick and easy adjustment of the truing mechanism, in combination with its convenient positioning on the cut from each grinding machine, provides for an appreciable overall saving in the grinding opera-tion.

Although the invention hasbeen specically described with reference to a pair of cooperating grinding wheels, it is to be understood that it is readily applicable to the dressing of any grinding wheel having a concavely formed peripheral surface. It is to be understood also that only a preferred embodiment of the invention has been described and illustrated herein and that modifications and alterations in this embodiment can be made which are within the full intended: scope ofv the invention as dened by the appended claims.

I claim:

1. In a grinding machine includingI frame means and a pair of cooperating grinding wheels rotatably mounted in said frame means having their axes in a common plane, said wheels hav'-Y ing concavely formed peripheral surfaces of like radius, the combination of means for dressing said surfaces including a base member slidably supported on said frame meansV above said wheels, a cutting tool for dressing said' wheels, carrying means'for said tool including a guiding sleeve supported in said base and extending downwardly therefrom between said wheels and' at right angles to said common plane, a hollow spindle rotatably supported in said-sleeve, a pivoted arm extending axially through said spindle,l said arm being pivotally movable within said spindle and having one end thereof extending to a point below the level of said commonv plane, with said tool being mounted at said one end, axis means on said spindle pivotally supporting said arm therein, adjustable means near the upper end of said spindle engageable with said arm to pivotally move the same to pivotally adjust the cutting edge of said tool relative tosaid common plane, adjustable means on said base member for linearly moving said tool to a cutting position relative to said peripheral surfaces, and means for rotating said spindle to in turn rotate said tool to successively dress said peripheral surfaces.

2. In a grinding machine having frame means and a pair of cooperating grinding wheels rotatably mounted in said frame means and formed with concavely curved said wheels having their axes in a common plane, the combination of means for dressing the grinding surfaces of said wheels to a like radius including a supporting member slidably supported on said frame means, a hollow spindle extending' through said supporting member and between said wheels at right angles to said plane, means rotatably supporting said spindle in said member, a dressing tool, a piVoted tool holder axially arranged in said spindle and having one end thereof extendingto a point below the level of said common plane, said tool being mounted at said one end, axis means in said spindle for pivotally supporting said tool holder, adjustable means at one end of said spindle engageable with` said tool holder to pivotally move the same tov pivotally adjust the cutting edge of said tool relative to said common plane, means for locking said tool holder in an adjusted position, adjust# able means on said supporting member for linearly moving said cutting edge in said plane to a cutting position-relative to said grinding surfaces, and means rotating said spindle to `in turn rotate said` tool grinding surfaces.

3. The combination with a grinding machine? grinding surfaces, with' to successively dress said.'

5 having frame means and a pair of cooperating' grinding. wheels rotatably mounted in said frame' meansV withV their axes ini ai conf-'muonv p'l'ane anditheir grinding surfaces of concave form, of means for' dressing. said grind-ing surfaces to a` like. radius including adressing t'ool, rotary means for carrying saidf dressing'tool, av n'ioui'iting member slidably s'upportedlonsaidframev means above said grinding wheels, means rotat' ably supporting said rotary means in said mounte ing member, said rotary means-r being positioned substantiallyv normal to said common plane andE having one endi thereof extending between said# wheels and to` a point below the' level of said.-4 common plane, with said dressing tool' being mounted at saidl one end andy with its cuttingedge in said plane, adjusting means on said" mounting member for moving the cutting edge' of said dressing tool subs'tantially in said plane" and into'a cuttingl position relative to saidgrindf ing surfaces, and means for rotating said rotary means to inl turn rotate saidI dressing toolr4 to'v successively dress saidgrinding' surfaces.

4'. A wheel dressing device for a grinding ma@ chine including frame means and a pair of c'ooperatinggrinding wheels having' their grinding surfaces of concave form and their axes in a' common horizontal plane, said dressing device' including al mounting member having a hori`- zontal portion and a' vertical portion, said vfiori-- zontal portion being slidably supported' on said' frame means, and saidvertical portion being' po#- sit'ioned above said wheels, and having a vertical bore therethrough, a stationary guiding' sleeve positioned in said bore'having one end extending downwardly'betwee'n said wh'e'e'ls' and' a't right' angles to said plane, a'hollow spindle' rotatably' supported in said sleeve; a pivoted arm axially" arranged in said spindle, axis means' in said' spindle pivotally supporting said' arm' intermediate its ends for pivotal movement' in said spindle, the lower end of' said arm being at said"v horizontal plane, a cutting tool mounted in said lower end ofthe arm, means in said spindlevpivotally moving said' arm to pivotally move the cutting edge of said tool relative to said horilzontal plane, means for locking the arm in an adjusted position, means slidably moving. saidv mounting member on said frame means to linearly move said tool into cutting position relativel to said'grinding surfaces, and means for rotating said spindle to in turn rotate said toolinto successive dressing surfaces.

5. A dressing device for on a pair of cooperating grinding wheels having concavely formed grinding surfaces and axes lyingY in a common plane, said device includinga. means slidably supportingv :said base member, a hollow spindle rotatably member at right angles to said1 base member, frame supported in said pivoted arm extending axially through said spindle andhavingone end portion` thereof at said vcommon plane, axis means in said: spindle i pivotally supporting. said arm for Apivotal movementwithinsaid spindle, witheach of thef end portions of said armbeing formedwithengagingv portions,

engagingv portions for guidably engaging saidarm end portions'whenl said -armis pivotally moved,l .a cutting. tool carried' bysaid` pivot'ed arm at'saidv one end'portiongadjustable means on said`v spindle engageable-with the-otheri endA iportion ofsaid 'arm' to'pivotally-movefsaid arm vengagement with said grinding-i putting the same radiusand said hollow spindle being. provided at eachendthereofwith corresponding,-

to swing the cutting edge of said cutting tool to said common plane, locking means at each end of said spindle to frictionally lock said arm in an adjusted and rigid position within said spindle for movement therewith, means linearly moving said base member to move said cutting tool to a cutting position relative to said grinding surfaces, and means for rotating said spindle to move said cutting tool over said grinding surfaces in succession.

6. In a grinding machine including frame means and a pair of cooperating grinding wheels rotatably mounted in said frame means and having their axes in a common horizontal plane, with said wheels having concavely formed peripheral surfaces of like radius, the combination of means for dressing said surfaces including a mounting member slidably supported on said frame means and having a vertically extending portion with a vertical bore therethrough projecting over said wheels, an elongated stationary sleeve mounted in said bore and having one end thereof extending downwardly between said wheels, a hollow spindle rotatably supported within said sleeve over substantially the entire length thereof, and having its lower end projecting outwardly from said one sleeve end, said spindle near each end thereof being provided with a pair of parallel flat sides, a pivoted arm within said spindle having one end at the said lower end of said spindle, a dressing tool mounted on said arm at said one end thereof, axis means pivotally supporting said arm for pivotal movement within said spindle, said arm having flat sides near each end thereof in guiding engagement with the corresponding flat sides in said spindle, adjustable means in said spindle pivotally moving said arm to pivotally swing the cutting edge of said tool into alignment with said common plane, means frictionally locking said corresponding engaging flat sides to rigidly lock said arm in an adjusted and xed position within said spindle, means linearly moving said mounting member to move said tool with its cutting edge in said plane into a cutting position relative to said peripheral surfaces, and means for rotating said spindle t move said tool successively across said concave surfaces.

"7. The combination with a grinding machine including frame mean and having a grinding wheel with a concavely formed peripheral grinding surface rotatably mounted` in said frame means, of means for dressing said wheel including a slidable mounting member removably supported on said frame means, said member having a portion projecting over said wheel with a bore extending vertically therethrough, an elongated guiding sleeve removably mounted in said member at said bore and at right angles to a horizontal plane including the axis of said wheel, means for1 frictionally locking said sleeve in a fixed position in said bore, a dressing tool, rotary means for carrying said tool rotatably supported in said sleeve and having an end portion at said plane, said tool being mounted in said end portion with its cutting edge in said plane, means linearly moving said mounting member to move said tool with its cutting edge in said plane to a cutting position relative to said peripheral surface, and means for rotating said rotary means to move said tool across said grinding surface, said latter means being mounted on said sleeve, with said sleeve and rotary means being removable from the bore in said mounting member as a unit and said mounting member being separately removable from said frame means to facilitate the assembly of said dressing device on said grinding machine.

8. In a grinding machine including frame means and a pair of cooperating grinding surfaced wheels rotatably mounted in said frame means, means for dressing the surfaces of said grinding wheels including in combination longitudinally adjustable means supported upon said frame means having a downwardly extending bore at one end, multi-part-wheel-dressing-tool carrying means movable in said bore and supported on said adjustable means, said multi-part carrying means including rotating means at one end thereof above said bore and surface dressing means at the other end thereof rotatable through 360 to dress the surface of each grinding wheel upon a single rotation thereof, with said rotation being accomplished by operation of said rotating means, and means supporting said surface dressing means for pivotal movement thereof in a path at right angles to the path of rotation thereof.

9. In a grinding machine including a pair of cooperating grinding wheels having their axes in a common plane, said wheels having peripheral surfaces of like radius, the Combination of means for dressing said surfaces including a frame portion arranged above said wheels, tool carrying means including stationary means carried on said frame portion and extended therefrom between said wheels in a direction normal to said common plane, rotatable means rotatably supported in said stationary means and projected outwardly from opposite ends thereof, and including an axially extended pivoted portion having one end at said common plane, a cutting tool supported in said one end of the pivoted portion, means at the opposite end of said pivoted portion for pivotally moving the same relative to the axis of said rotatable means, thereby to adjust the cutting portion of said cutting tool substantially in said common plane, additional means for adjusting said cutting portion in said common plane relative to the peripheral surfaces of said wheels, and means rotating said rotatable means to successively dress said peripheral surfaces.

10. The combination with a grinding machine having movable frame means and a pair of cooperating grinding wheels rotatably mounted in said frame means with their axes in a common plane, of means for dressing the grinding surfaces of said Wheels to alike radius including a dressing tool, a portion fixed on said frame means located above and intermediate said grinding wheels, a rotary portion rotatably supported in said fixed portion and projected outwardly from opposite ends thereof, said rotary portion being positioned substantially normal to said common plane, pivoted means carried in said rotary portion for rotation therewith, but for pivotal movement relative thereto in a plane normal to said common plane, said pivoted means having one end at said common plane, with said dressing tool being mounted on said pivoted means at said one end, means acting on the opposite end of said pivoted means to pivotally move the same relative to the axis of said rotatable means, thereby to adjust the cutting portion of said dressing tool substantially in said common plane, means for moving said frame means, fixed portion and rotary portion as a unit to `adjust said cutting portion in said cornmon plane relative to said grinding surfaces, and means for rotating said rotary portion to rotate said dressing tool to successively dress said grinding surfaces.

11. A wheel dressing device for a grinding machine having a wheel with an axis and a grinding surface, said dressing device including a movable frame portion located outwardly from the periphery of said wheel, a bearing portion fixedly supported at one end on said frame portion, with an opposite end thereof projected outwardly from said frame portion in a direction toward said wheel and normal to a plane passing through the axis of said wheel, with said opposite end extending substantially to said plane, a rotary portion rotatably supported in said bearing portion and substantially coextensive in length therewith, pivoted means pivotally supported in said rotary portion for rotation therewith having one end at said plane, a dressing tool carried in the one end of said pivoted means, adjustable means acting on the opposite end of said pivoted means to pivotally move the same relative to said rotary portion in a path normal to said plane to adjust the cutting edge thereof relative to said plane, means for adjustably moving said frame portion to move said cutting edge, while in said plane, relative to said grinding surface, and means rotating said rotary portion to rotate said dressing tool to dress said grinding surface.

12. A grinding Wheel dressing unit adapted for mounting upon a grinding machine to dress the surface of the grinding wheel including, in combination, frame means including a rst straight elongated tubular member adapted to extend generally toward the surface to be dressed, a second straight elongated tubular member rotatably supported within and partially housed by said first tubular member, means for rotating said second tubular member within said lirst tubular member, an elongated tool holding bar mounted within said second tubular member for rotation therewith and pivotally mounted intermediate its ends upon said second tubular member for pivotal movement relative to said second tubular member, said tool holding bar being substantially completely housed by said second tubular member, means for adjusting said tool holding bar about its pivot relative to said second tubular member, and a dressing tool mounted at one end of said tool holding bar for pivotal movement with said bar to a wheel dressing position and for rotation with said tool holding bar and said rotary means through a single plane at said dressing position.

OTTO STORZ'. 

